Millimetric radios at 23, 38, 50, 55 GHz can have permissible frequency drifts of .+-.400 to .+-.800 KHz at each terminal. Therefore the error in the receiver IF signal may be up to .+-.1.6 MHz.
The optimum IF filter bandwidths are in the range of 3 MHz for low data rates (1 or 2.times.2 megabits). Hence without frequency correction, the filter bandwidth would have to be widened out to .apprxeq.6 MHz. This would impact the receiver noise bandwidth and therefore system sensitivity.